The present invention relates to a method of and an arrangement for lifting and gripping a starting portion of a film, located in a coil
More particularly, it relates to such a method and an arrangement in accordance with which a separating wedge abuts with prestressing on an outer surface of the coil and its edge lifts the starting portion of the film from the coil, and a transporting moves the lifted starting portion of the film to a subsequent mechanical system.
Methods and arrangements of the above mentioned general type are known in the art. One of such methods and arrangements is disclosed for example in the U.S. Pat. No. 3,733,036. In the arrangement described in this reference a separating wedge abuts with pretensioning on the coil of a roll film, and the coil is rotated in an uncoiling direction. The separating wedge wraps over the outer surface of the film coil, engages under the end edge at the starting portion of the film and releases the starting portion of the film from the coil. This solution, however, has the disadvantage that due to the friction forces between the outer surface of the film and the separating wedge, the uppermost coil layer is displaced and the film is loosened. Therefore a loop is produced. This can lead to the situation when the separating wedge does not engage the end edge and an automatic threading in is no longer possible.